市场效率一市场失灵 Market Efficiency-Market Failures 外部性 Externalities 国顾:亚当斯密认为,市场的“看不见的手引导着市场中 自和的买者和卖者,使社会获得了可以从市场获得的最大收 Recall that: Adam Smith's " invisible hand" of the 第10章 arketplace leads self-interested buyers and sellers in a market to maximize the total benefit that society can derive Cha pter 10 from a market 但是市场失灵依然会发生。 ket fail 市场失灵:外部性 外部性产生于 Market Failures: Externalities An externality arises ◆当市场结果影响到了除市场中买者和卖者以 外的其他方,产生的副作用就称为外部性。 When a market outcome affects parties 当某一个人从事的活动影响了旁 other than the buyers and sellers in the 观者的福利,而对这种影响既不支 market, side-effects created are called 付也没有获得任何赔偿。 externalities when a person engages in an hat influences the well-being of ◆外部性引起了市场的无效率,因此不能使得 bystander and yet neither pay 总剩余最大化 receives any compensation for that effect. Externalities cause markets to be inefficient and thus fail to maximize total surplus. 市场失灵:外部性 负外部性的例子 Market Failures: Externalities Examples of Negative Externalities ◆当对旁人的影响是不利的,外部性被 称作是负外部性。 ◆汽车尾气 Automobile exhaust When the impact on the bystander is ◆抽烟 Cigarette smoking adverse, the externality is called a ◆狗叫 Barking dogs negative externality. ◆公寓楼里面高音播放的立体声音响 °亲种企的影是有的,外部性数 Loud stereos in an apartment building When the impact on the bystander is beneficial. the externality is called a positive externality
1 外部性 Externalities 第10章 Chapter 10 2 市场效率—市场失灵 Market Efficiency - Market Failures 回顾： 亚当·斯密认为，市场的“看不见的手”引导着市场中 自利的买者和卖者，使社会获得了可以从市场获得的最大收 益。 Recall that: Adam Smith’s “invisible hand” of the marketplace leads self-interested buyers and sellers in a market to maximize the total benefit that society can derive from a market. 但是市场失灵依然会发生。 But market failures can still happen. 3 市场失灵：外部性 Market Failures: Externalities 当市场结果影响到了除市场中买者和卖者以 外的其他方，产生的副作用就称为外部性。 When a market outcome affects parties other than the buyers and sellers in the market, side-effects created are called externalities. 外部性引起了市场的无效率，因此不能使得 总剩余最大化。 Externalities cause markets to be inefficient, and thus fail to maximize total surplus. 4 外部性产生于… An externality arises... . . .当某一个人从事的活动影响了旁 观者的福利，而对这种影响既不支 付也没有获得任何赔偿。 …when a person engages in an activity that influences the well-being of a bystander and yet neither pays nor receives any compensation for that effect. 5 市场失灵：外部性 Market Failures: Externalities 当对旁人的影响是不利的，外部性被 称作是负外部性。 When the impact on the bystander is adverse, the externality is called a negative externality. 当对旁人的影响是有益的，外部性被 称作是正外部性。 When the impact on the bystander is beneficial, the externality is called a positive externality. 6 汽车尾气 Automobile exhaust 抽烟 Cigarette smoking 狗叫 Barking dogs 公寓楼里面高音播放的立体声音响 Loud stereos in an apartment building 负外部性的例子 Examples of Negative Externalities
正外部性的例子 铝市场 Examples of Positive The Market for Aluminum Externalities 铝的价格 ◆免疫注射 Immunizations 厂麻 private cost ◆修复历史性建筑物 Restored historic buildings ◆研究新技术 Research into new technolo 名人价筐 private value) 铝的堂量8 铝市场与福利经济 铝市场与福利经济 The Market for Aluminum and The Market for Aluminum and Welfare economics Welfare economics 市场均衡时生产和消费的数量,从使 如果铝厂排污(负外部性),那么社会生产 生产者与消费者剩余之和最大化的意 铝的成本就会比铝生产者支付的成本高 义上来说,是有效率的。 If the aluminum factories emit pollution(a The quantity produced and consumed negative externality ) then the cost to society in the market equilibrium is efficient of producing aluminum is larger than the cost to aluminum producers. in the sense that it maximizes the sum of producer and consumer surplus. 铝市场与福利经济 污染与社会最优 The Market for Aluminum and Pollution and the Social Optimum. Welfare Economics 污录成 对于生产的每一单位的铝而言,社会成本包 括生产者的私人成本,加上向受到污染不利 影响的旁观者施加的成本 均衡 Equilibrium For each unit of aluminum produced, the social cost includes the private costs of the producers plus the cost to those bystanders adversely affected by the pollution CMaRKET
2 7 免疫注射 Immunizations 修复历史性建筑物 Restored historic buildings 研究新技术 Research into new technologies 正外部性的例子 Examples of Positive Externalities 8 铝市场 The Market for Aluminum... 铝的数量 Quantity of Aluminum 0 铝的价格 Price of Aluminum QMARKET 需求Demand (私人价值 private value) 供给Supply (厂商成本 private cost) 均衡点 Equilibrium 9 铝市场与福利经济 The Market for Aluminum and Welfare Economics 市场均衡时生产和消费的数量，从使 生产者与消费者剩余之和最大化的意 义上来说，是有效率的。 The quantity produced and consumed in the market equilibrium is efficient in the sense that it maximizes the sum of producer and consumer surplus. 10 铝市场与福利经济 The Market for Aluminum and Welfare Economics 如果铝厂排污（负外部性），那么社会生产 铝的成本就会比铝生产者支付的成本高。 If the aluminum factories emit pollution (a negative externality), then the cost to society of producing aluminum is larger than the cost to aluminum producers. 11 铝市场与福利经济 The Market for Aluminum and Welfare Economics 对于生产的每一单位的铝而言，社会成本包 括生产者的私人成本，加上向受到污染不利 影响的旁观者施加的成本。 For each unit of aluminum produced, the social cost includes the private costs of the producers plus the cost to those bystanders adversely affected by the pollution. QMARKET 12 污染与社会最优… Pollution and the Social Optimum… 铝数量 Quantity of Aluminum 0 铝价格 Price of Aluminum 需求Demand (私人价值private value) 供给Supply (厂商成本private cost) 社会成本 Social cost Qoptimum 污染成本 Cost of pollution 均衡Equilibrium 最优 Optimum
生产中的负外部性 实现社会最优产出 negative Externalities in Achieving the Socially Optimal Production Output 需求曲线和社会成本曲线的交点决定了最优产出水 外部性的内在化(内部化)涉及改变激 The intersection of the demand curve and the 励机制,使得人们在生产时考虑其对外 social-cost curve determines the optimal output 部的影响。 Internalizing an externality involves ◆社会最优产出水平小于市场均衡值 altering incentives so that people take The socially optimal output level is less than into account the external effects of their he market equilibrium quantity. actions 实现社会最优产出 生产中的正外部性 Achieving the Socially Optimal Positive Externalities in Output Production 政府通过对厂商征税,把均衡产量减至社 当外部性使旁观者受益时,正的外部性便产生了 会所期望的水平,实现外部性的内在化。 When an externality benefits the bystanders, a The government can internalize an positive externality exists. externality by imposing a tax on the ◆生产的社会成本小于生产者和消费者付出的 私人成本 producer to reduce the equilibrium The social costs of production are less than the quantity to the socially desirable quantity private cost to producers and consumers. 生产中的正外部性 生产中的正外部性 Positive Externalities in Production Positive Externalities in 机人价备 Production Price of Robot 术抛出曲值 狐人成本 private cost) 社金成本 Social cost 技术外溢是一种正外部性,出现在当公司的创 新或设计不仅使本公司受益,而且进入了社会 的技术知识库并使得全社会受益的时候 A technology spillover is a type of positive externality that exists when a firm's innovation or design not only benefits the firm, but enters societys pool of technological knowledge and benefits society as a whole. 人你Qmn CMARKET QOPTIHUM 机事人量
3 13 生产中的负外部性 Negative Externalities in Production 需求曲线和社会成本曲线的交点决定了最优产出水 平。 The intersection of the demand curve and the social-cost curve determines the optimal output level. 社会最优产出水平小于市场均衡值。 The socially optimal output level is less than the market equilibrium quantity. 14 实现社会最优产出 Achieving the Socially Optimal Output 外部性的内在化（内部化）涉及改变激 励机制，使得人们在生产时考虑其对外 部的影响。 Internalizing an externality involves altering incentives so that people take into account the external effects of their actions. 15 实现社会最优产出 Achieving the Socially Optimal Output 政府通过对厂商征税，把均衡产量减至社 会所期望的水平，实现外部性的内在化。 The government can internalize an externality by imposing a tax on the producer to reduce the equilibrium quantity to the socially desirable quantity. 16 生产中的正外部性 Positive Externalities in Production 当外部性使旁观者受益时，正的外部性便产生了 When an externality benefits the bystanders, a positive externality exists. 生产的社会成本小于生产者和消费者付出的 私人成本。 The social costs of production are less than the private cost to producers and consumers. 17 生产中的正外部性 Positive Externalities in Production 技术外溢是一种正外部性，出现在当公司的创 新或设计不仅使本公司受益，而且进入了社会 的技术知识库并使得全社会受益的时候。 A technology spillover is a type of positive externality that exists when a firm’s innovation or design not only benefits the firm, but enters society’s pool of technological knowledge and benefits society as a whole. 生产中的正外部性… Positive Externalities in Production… 机器人数量 Quality of Robots 0 机器人价格 Price of Robot QOPTIMUM 需求 Demand (私人价值 private value) 供给 Supply (私人成本 private cost) 社会成本 Social cost QMARKET 技术溢出值 Value of technology spillover 均衡 Equilibrium 最优 Optimum
生产中的正外部性 Positive Externalities in 外部性的内在化:补贴 Production Internalizing Externalities 需求曲线和社会成本曲线的交点决定了最优产出水平 Subsidies The intersection of the demand curve and the social-cost urve determines the optimal output leveL. 政府经常使用补贴的方法试图将 ◆最优产出水平高于均衡数量。 正外部性内在化。 The optimal output level is more than the equilibrium quantity. Government many times uses ◆市场产出量低于社会希望的数量。 subsidies as the primary method The market produces a smaller quantity than is socially desirable for attempting to internalize ◆产出的社会成本小于厂商和消费者支付的私人成本 positive externalities. The social costs of production are less than the private cost to producers and consumers. 技术政策 技术政策 Technology Policy Technology Policy ◆专利法是技术政策的一种,它对个人或 政府干预经济以扶持高技术产业的 企业创造发明的产权予以专利保护 Patent laws are a form of technology 做法,称为技术政策。 policy that give the individual (or firm) Government intervention in the with patent protection a property right over its invention economy that aims to promote technology-enhancing industries is ◆因此,可以说专利使外部性内在化 The patent is then said to internalize the called technology policy externality 生产外部性的内在化 internalizing Production 消费的外部性 Consumption Extemalities Externalities (b)正的精冀外都性 税收是被用来把负外部性内在化的主 Positive Consumption Externality 要工具 Taxes are the primary tools used to internalize negative externalities ◆补贴是被用来把正外部性内在化的主 要工具 Subsidies are the primary tools used value) to internalize positive externalities
4 19 生产中的正外部性 Positive Externalities in Production 需求曲线和社会成本曲线的交点决定了最优产出水平。 The intersection of the demand curve and the social-cost curve determines the optimal output level. 最优产出水平高于均衡数量。 The optimal output level is more than the equilibrium quantity. 市场产出量低于社会希望的数量。 The market produces a smaller quantity than is socially desirable. 产出的社会成本小于厂商和消费者支付的私人成本 The social costs of production are less than the private cost to producers and consumers. 20 外部性的内在化：补贴 Internalizing Externalities: Subsidies 政府经常使用补贴的方法试图将 正外部性内在化。 Government many times uses subsidies as the primary method for attempting to internalize positive externalities. 21 技术政策 Technology Policy 政府干预经济以扶持高技术产业的 做法，称为技术政策。 Government intervention in the economy that aims to promote technology-enhancing industries is called technology policy. 22 技术政策 Technology Policy 专利法是技术政策的一种，它对个人或 企业创造发明的产权予以专利保护。 Patent laws are a form of technology policy that give the individual (or firm) with patent protection a property right over its invention. 因此，可以说专利使外部性内在化。 The patent is then said to internalize the externality. 23 生产外部性的内在化 Internalizing Production Externalities 税收是被用来把负外部性内在化的主 要工具。 Taxes are the primary tools used to internalize negative externalities. 补贴是被用来把正外部性内在化的主 要工具。 Subsidies are the primary tools used to internalize positive externalities. 24 消费的外部性… Consumption Externalities… 教育量 Quantity of Education 0 教育价格 (Price of Education) Q 市场 MARKET 需求Demand (私人价值private value) 社会价值 Social value Q 最优 OPTIMUM (b)正的消费外部性 Positive Consumption Externality 供给Supply (私人成本 private cost) 酒精量 Quantity of Alcohol 0 酒精价格 (Price of Alcohol) Q 市场值 MARKET 需求Demand (私人价值 private value) 供给Supply (私人成本private cost) 社会价值 Social value Q 最优值 OPTIMUM (a) 负的消费外部性 Negative Consumption Externality
外部性与市场无效率 Externalities and market 外部性的私人解决方法 Inefficiency Private Solutions to ◆生产或消费中的负外部性使得市场的产量比 社会希望的要多 Externalities Negative externalities in production or consumption lead markets to produce a larger 并不总是需要政府行为来解决 quantity than is socially desirable. 外部性问题。 ◆生产或消费中的正外部性使得市场的产量比 Government action is not 社会希望的要少。 Positive externalities in production or always needed to solve the consumption lead markets to produce a larger problem of externalities. quantity than is socially desirable. 外部性的私人解决方法的类型 Types of Private Solutions to 科斯定理 Externalities The Coase Theorem ◆道德规范和社会约束 科斯定理:如果当事各方能够就资源配置无成本 Moral codes and social sanctions 地进行讨价还价(交易),那么私人市场总能自 ◆慈善组织 行解决外部性问题,并有效率地配置资源 The Coase Theorem states that if private parties Charitable organizations can bargain without cost over the allocation of ◆把不同经营类型的商业组织合并 resources, then the private market will always Integrating different types of businesses solve the problem of externalities on its own and ◆利益各方签定合约 allocate resources efficiently Contracting between parties 科斯定理的例子 科斯定理的例子 The Coase Theorem: An Example The Coase Theorem: An Example ◆张三和李四同居一室。张喜欢在宿舍里大 声放音乐,影响了李的学习。 ◆假定学校规定不得在宿舍吵闹。这样,学校将 ◆一般的想法:把管理员请来,宣读学校规 初娘利交给了安静的一方(李四):但同时 定,让张三关掉声音。 允许双方协商解决,无论最终结果如何 ◆经济学家的问题 ◆假定张三从音乐得到的享受(50元)高于对李 ◆为什么一定要让张三最终关掉声音? 四引起的成本(40元)。换句话说,张三最多 ◆有没有可能在双方自愿的情况下解决问 愿意花50元钱,以征得李四放弃安静的权利。 而李四在至少得到40元钱的情况下,就同意放 弃安静的权利。 ◆自愿解决的结果是好的结果吗?
5 25 外部性与市场无效率 Externalities and Market Inefficiency 生产或消费中的负外部性使得市场的产量比 社会希望的要多。 Negative externalities in production or consumption lead markets to produce a larger quantity than is socially desirable. 生产或消费中的正外部性使得市场的产量比 社会希望的要少。 Positive externalities in production or consumption lead markets to produce a larger quantity than is socially desirable. 26 外部性的私人解决方法 Private Solutions to Externalities 并不总是需要政府行为来解决 外部性问题。 Government action is not always needed to solve the problem of externalities. 27 外部性的私人解决方法的类型 Types of Private Solutions to Externalities 道德规范和社会约束 Moral codes and social sanctions 慈善组织 Charitable organizations 把不同经营类型的商业组织合并 Integrating different types of businesses 利益各方签定合约 Contracting between parties 28 科斯定理 The Coase Theorem 科斯定理：如果当事各方能够就资源配置无成本 地进行讨价还价（交易），那么私人市场总能自 行解决外部性问题，并有效率地配置资源。 The Coase Theorem states that if private parties can bargain without cost over the allocation of resources, then the private market will always solve the problem of externalities on its own and allocate resources efficiently. 29 科斯定理的例子 The Coase Theorem：An Example 张三和李四同居一室。张喜欢在宿舍里大 声放音乐，影响了李的学习。 一般的想法：把管理员请来，宣读学校规 定，让张三关掉声音。 经济学家的问题 为什么一定要让张三最终关掉声音？ 有没有可能在双方自愿的情况下解决问 题？ 自愿解决的结果是好的结果吗？ 30 科斯定理的例子 The Coase Theorem：An Example 假定学校规定不得在宿舍吵闹。这样，学校将 初始权利交给了安静的一方（李四）；但同时 允许双方协商解决，无论最终结果如何。 假定张三从音乐得到的享受（50元）高于对李 四引起的成本（40元）。换句话说，张三最多 愿意花50元钱，以征得李四放弃安静的权利。 而李四在至少得到40元钱的情况下，就同意放 弃安静的权利